1. Field of the Invention
The present invention relates to an optical axis control assembly for headlights at the front of a vehicle.
2. Description of the Related Art
Conventionally, two electronic control units of the same configuration are used to control lighting of HID or similar discharge lamps mounted as headlights of a vehicle at the front thereof as disclosed in Japanese Pat. Appln. Kokai Pub. No. 91436/99 and Japanese Pat. Appln. Kokai Pub. No. 91437/99. The one electronic control unit having connected thereto various sensors works as a main electronic control unit, which computes a controlled variable of each discharge lamp in the direction of its optical axis and sends the computed value to the other electronic control unit to control the optical axes of the right and left discharge lamps in equal proportion. In this way, two electronic control units of the same function are used to appropriately control the optical axes of the right and left discharge lamps at the front of the vehicle without causing any deviation from each other.
The conventional optical axis control scheme uses, as mentioned above, electronic control units capable of controlling the optical axes of the right and left discharge lamps independently of each other, but since full information for computing the tilt angle of the car body is input to only one of the two electronic control units, constituent elements of the other electronic control unit for optical axis determination are totally useless.
The provision of such useless constituent elements, which are not actually used for receiving information, such as a connector and similar parts, inevitably raises the cost of the electronic control assembly, and unnecessarily consumes space due to the magnification of the electronic control unit, impairing the utilization efficiency of limited space of the car body.